dump: add Windows dump format to dump-guest-memory

This patch adds Windows crashdumping feature. Now QEMU can produce ELF-dump
containing Windows crashdump header, which can help to convert to a valid
WinDbg-understandable crashdump file, or immediately create such file.
The crashdump will be obtained by joining physical memory dump and 8K header
exposed through vmcoreinfo/fw_cfg device by guest driver at BSOD time. Option
'-w' was added to dump-guest-memory command. At the moment, only x64
configuration is supported.
Suitable driver can be found at
https://github.com/virtio-win/kvm-guest-drivers-windows/tree/master/fwcfg64

Signed-off-by: Viktor Prutyanov <viktor.prutyanov@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180517162342.4330-2-viktor.prutyanov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/dump.c b/dump.c
index b54cd42b21..04467b353e 100644
--- a/dump.c
+++ b/dump.c
@@ -29,6 +29,10 @@
 #include "qemu/error-report.h"
 #include "hw/misc/vmcoreinfo.h"
 
+#ifdef TARGET_X86_64
+#include "win_dump.h"
+#endif
+
 #include <zlib.h>
 #ifdef CONFIG_LZO
 #include <lzo/lzo1x.h>
@@ -1866,7 +1870,11 @@ static void dump_process(DumpState *s, Error **errp)
     Error *local_err = NULL;
     DumpQueryResult *result = NULL;
 
-    if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+    if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
+#ifdef TARGET_X86_64
+        create_win_dump(s, &local_err);
+#endif
+    } else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
         create_kdump_vmcore(s, &local_err);
     } else {
         create_vmcore(s, &local_err);
@@ -1970,6 +1978,13 @@ void qmp_dump_guest_memory(bool paging, const char *file,
     }
 #endif
 
+#ifndef TARGET_X86_64
+    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
+        error_setg(errp, "Windows dump is only available for x86-64");
+        return;
+    }
+#endif
+
 #if !defined(WIN32)
     if (strstart(file, "fd:", &p)) {
         fd = monitor_get_fd(cur_mon, p, errp);
@@ -2044,5 +2059,12 @@ DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
     item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
 #endif
 
+    /* Windows dump is available only if target is x86_64 */
+#ifdef TARGET_X86_64
+    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
+    item = item->next;
+    item->value = DUMP_GUEST_MEMORY_FORMAT_WIN_DMP;
+#endif
+
     return cap;
 }